This proposal deals with both the mechanisms of action of lymphokines and the use of the mouse as a model strain for studying lymphokine function. We have demonstrated non-H-2-dependent strain variation in MIF production, a lack of strain variation in target cell response to MIF, and the capacity of the B as well as T mouse lymphocyte to produce MIF. Currently, we are extending studies on strain variation of MIF production to include lymphocyte subpopulations and in vivo manifestations. Concurrently with these studies we are evaluating the ability of lymphokine inhibitors such as monosaccharides to influence cellular immune responses in vivo.